fs/ceph/mds_client.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _FS_CEPH_MDS_CLIENT_H
   3 #define _FS_CEPH_MDS_CLIENT_H
   4
   5 #include <linux/completion.h>
   6 #include <linux/kref.h>
   7 #include <linux/list.h>
   8 #include <linux/mutex.h>
   9 #include <linux/rbtree.h>
  10 #include <linux/spinlock.h>
  11 #include <linux/refcount.h>
  12 #include <linux/utsname.h>
  13
  14 #include <linux/ceph/types.h>
  15 #include <linux/ceph/messenger.h>
  16 #include <linux/ceph/mdsmap.h>
  17 #include <linux/ceph/auth.h>
  18
  19 /* The first 8 bits are reserved for old ceph releases */
  20 #define CEPHFS_FEATURE_MIMIC    8
  21
  22 #define CEPHFS_FEATURES_ALL {           \
  23   0, 1, 2, 3, 4, 5, 6, 7,               \
  24   CEPHFS_FEATURE_MIMIC,                 \
  25 }
  26
  27 #define CEPHFS_FEATURES_CLIENT_SUPPORTED CEPHFS_FEATURES_ALL
  28 #define CEPHFS_FEATURES_CLIENT_REQUIRED {}
  29
  30
  31 /*
  32  * Some lock dependencies:
  33  *
  34  * session->s_mutex
  35  *         mdsc->mutex
  36  *
  37  *         mdsc->snap_rwsem
  38  *
  39  *         ci->i_ceph_lock
  40  *                 mdsc->snap_flush_lock
  41  *                 mdsc->cap_delay_lock
  42  *
  43  */
  44
  45 struct ceph_fs_client;
  46 struct ceph_cap;
  47
  48 /*
  49  * parsed info about a single inode.  pointers are into the encoded
  50  * on-wire structures within the mds reply message payload.
  51  */
  52 struct ceph_mds_reply_info_in {
  53         struct ceph_mds_reply_inode *in;
  54         struct ceph_dir_layout dir_layout;
  55         u32 symlink_len;
  56         char *symlink;
  57         u32 xattr_len;
  58         char *xattr_data;
  59         u64 inline_version;
  60         u32 inline_len;
  61         char *inline_data;
  62         u32 pool_ns_len;
  63         char *pool_ns_data;
  64         u64 max_bytes;
  65         u64 max_files;
  66 };
  67
  68 struct ceph_mds_reply_dir_entry {
  69         char                          *name;
  70         u32                           name_len;
  71         struct ceph_mds_reply_lease   *lease;
  72         struct ceph_mds_reply_info_in inode;
  73         loff_t                        offset;
  74 };
  75
  76 /*
  77  * parsed info about an mds reply, including information about
  78  * either: 1) the target inode and/or its parent directory and dentry,
  79  * and directory contents (for readdir results), or
  80  * 2) the file range lock info (for fcntl F_GETLK results).
  81  */
  82 struct ceph_mds_reply_info_parsed {
  83         struct ceph_mds_reply_head    *head;
  84
  85         /* trace */
  86         struct ceph_mds_reply_info_in diri, targeti;
  87         struct ceph_mds_reply_dirfrag *dirfrag;
  88         char                          *dname;
  89         u32                           dname_len;
  90         struct ceph_mds_reply_lease   *dlease;
  91
  92         /* extra */
  93         union {
  94                 /* for fcntl F_GETLK results */
  95                 struct ceph_filelock *filelock_reply;
  96
  97                 /* for readdir results */
  98                 struct {
  99                         struct ceph_mds_reply_dirfrag *dir_dir;
 100                         size_t                        dir_buf_size;
 101                         int                           dir_nr;
 102                         bool                          dir_end;
 103                         bool                          dir_complete;
 104                         bool                          hash_order;
 105                         bool                          offset_hash;
 106                         struct ceph_mds_reply_dir_entry  *dir_entries;
 107                 };
 108
 109                 /* for create results */
 110                 struct {
 111                         bool has_create_ino;
 112                         u64 ino;
 113                 };
 114         };
 115
 116         /* encoded blob describing snapshot contexts for certain
 117            operations (e.g., open) */
 118         void *snapblob;
 119         int snapblob_len;
 120 };
 121
 122
 123 /*
 124  * cap releases are batched and sent to the MDS en masse.
 125  *
 126  * Account for per-message overhead of mds_cap_release header
 127  * and __le32 for osd epoch barrier trailing field.
 128  */
 129 #define CEPH_CAPS_PER_RELEASE ((PAGE_SIZE - sizeof(u32) -               \
 130                                 sizeof(struct ceph_mds_cap_release)) /  \
 131                                 sizeof(struct ceph_mds_cap_item))
 132
 133
 134 /*
 135  * state associated with each MDS<->client session
 136  */
 137 enum {
 138         CEPH_MDS_SESSION_NEW = 1,
 139         CEPH_MDS_SESSION_OPENING = 2,
 140         CEPH_MDS_SESSION_OPEN = 3,
 141         CEPH_MDS_SESSION_HUNG = 4,
 142         CEPH_MDS_SESSION_CLOSING = 5,
 143         CEPH_MDS_SESSION_RESTARTING = 6,
 144         CEPH_MDS_SESSION_RECONNECTING = 7,
 145         CEPH_MDS_SESSION_REJECTED = 8,
 146 };
 147
 148 struct ceph_mds_session {
 149         struct ceph_mds_client *s_mdsc;
 150         int               s_mds;
 151         int               s_state;
 152         unsigned long     s_ttl;      /* time until mds kills us */
 153         u64               s_seq;      /* incoming msg seq # */
 154         struct mutex      s_mutex;    /* serialize session messages */
 155
 156         struct ceph_connection s_con;
 157
 158         struct ceph_auth_handshake s_auth;
 159
 160         /* protected by s_gen_ttl_lock */
 161         spinlock_t        s_gen_ttl_lock;
 162         u32               s_cap_gen;  /* inc each time we get mds stale msg */
 163         unsigned long     s_cap_ttl;  /* when session caps expire */
 164
 165         /* protected by s_cap_lock */
 166         spinlock_t        s_cap_lock;
 167         struct list_head  s_caps;     /* all caps issued by this session */
 168         int               s_nr_caps, s_trim_caps;
 169         int               s_num_cap_releases;
 170         int               s_cap_reconnect;
 171         int               s_readonly;
 172         struct list_head  s_cap_releases; /* waiting cap_release messages */
 173         struct ceph_cap  *s_cap_iterator;
 174
 175         /* protected by mutex */
 176         struct list_head  s_cap_flushing;     /* inodes w/ flushing caps */
 177         unsigned long     s_renew_requested; /* last time we sent a renew req */
 178         u64               s_renew_seq;
 179
 180         refcount_t          s_ref;
 181         struct list_head  s_waiting;  /* waiting requests */
 182         struct list_head  s_unsafe;   /* unsafe requests */
 183 };
 184
 185 /*
 186  * modes of choosing which MDS to send a request to
 187  */
 188 enum {
 189         USE_ANY_MDS,
 190         USE_RANDOM_MDS,
 191         USE_AUTH_MDS,   /* prefer authoritative mds for this metadata item */
 192 };
 193
 194 struct ceph_mds_request;
 195 struct ceph_mds_client;
 196
 197 /*
 198  * request completion callback
 199  */
 200 typedef void (*ceph_mds_request_callback_t) (struct ceph_mds_client *mdsc,
 201                                              struct ceph_mds_request *req);
 202 /*
 203  * wait for request completion callback
 204  */
 205 typedef int (*ceph_mds_request_wait_callback_t) (struct ceph_mds_client *mdsc,
 206                                                  struct ceph_mds_request *req);
 207
 208 /*
 209  * an in-flight mds request
 210  */
 211 struct ceph_mds_request {
 212         u64 r_tid;                   /* transaction id */
 213         struct rb_node r_node;
 214         struct ceph_mds_client *r_mdsc;
 215
 216         int r_op;                    /* mds op code */
 217
 218         /* operation on what? */
 219         struct inode *r_inode;              /* arg1 */
 220         struct dentry *r_dentry;            /* arg1 */
 221         struct dentry *r_old_dentry;        /* arg2: rename from or link from */
 222         struct inode *r_old_dentry_dir;     /* arg2: old dentry's parent dir */
 223         char *r_path1, *r_path2;
 224         struct ceph_vino r_ino1, r_ino2;
 225
 226         struct inode *r_parent;             /* parent dir inode */
 227         struct inode *r_target_inode;       /* resulting inode */
 228
 229 #define CEPH_MDS_R_DIRECT_IS_HASH       (1) /* r_direct_hash is valid */
 230 #define CEPH_MDS_R_ABORTED              (2) /* call was aborted */
 231 #define CEPH_MDS_R_GOT_UNSAFE           (3) /* got an unsafe reply */
 232 #define CEPH_MDS_R_GOT_SAFE             (4) /* got a safe reply */
 233 #define CEPH_MDS_R_GOT_RESULT           (5) /* got a result */
 234 #define CEPH_MDS_R_DID_PREPOPULATE      (6) /* prepopulated readdir */
 235 #define CEPH_MDS_R_PARENT_LOCKED        (7) /* is r_parent->i_rwsem wlocked? */
 236         unsigned long   r_req_flags;
 237
 238         struct mutex r_fill_mutex;
 239
 240         union ceph_mds_request_args r_args;
 241         int r_fmode;        /* file mode, if expecting cap */
 242         kuid_t r_uid;
 243         kgid_t r_gid;
 244         struct timespec64 r_stamp;
 245
 246         /* for choosing which mds to send this request to */
 247         int r_direct_mode;
 248         u32 r_direct_hash;      /* choose dir frag based on this dentry hash */
 249
 250         /* data payload is used for xattr ops */
 251         struct ceph_pagelist *r_pagelist;
 252
 253         /* what caps shall we drop? */
 254         int r_inode_drop, r_inode_unless;
 255         int r_dentry_drop, r_dentry_unless;
 256         int r_old_dentry_drop, r_old_dentry_unless;
 257         struct inode *r_old_inode;
 258         int r_old_inode_drop, r_old_inode_unless;
 259
 260         struct ceph_msg  *r_request;  /* original request */
 261         int r_request_release_offset;
 262         struct ceph_msg  *r_reply;
 263         struct ceph_mds_reply_info_parsed r_reply_info;
 264         struct page *r_locked_page;
 265         int r_err;
 266
 267         unsigned long r_timeout;  /* optional.  jiffies, 0 is "wait forever" */
 268         unsigned long r_started;  /* start time to measure timeout against */
 269         unsigned long r_request_started; /* start time for mds request only,
 270                                             used to measure lease durations */
 271
 272         /* link unsafe requests to parent directory, for fsync */
 273         struct inode    *r_unsafe_dir;
 274         struct list_head r_unsafe_dir_item;
 275
 276         /* unsafe requests that modify the target inode */
 277         struct list_head r_unsafe_target_item;
 278
 279         struct ceph_mds_session *r_session;
 280
 281         int               r_attempts;   /* resend attempts */
 282         int               r_num_fwd;    /* number of forward attempts */
 283         int               r_resend_mds; /* mds to resend to next, if any*/
 284         u32               r_sent_on_mseq; /* cap mseq request was sent at*/
 285
 286         struct kref       r_kref;
 287         struct list_head  r_wait;
 288         struct completion r_completion;
 289         struct completion r_safe_completion;
 290         ceph_mds_request_callback_t r_callback;
 291         ceph_mds_request_wait_callback_t r_wait_for_completion;
 292         struct list_head  r_unsafe_item;  /* per-session unsafe list item */
 293
 294         long long         r_dir_release_cnt;
 295         long long         r_dir_ordered_cnt;
 296         int               r_readdir_cache_idx;
 297         u32               r_readdir_offset;
 298
 299         struct ceph_cap_reservation r_caps_reservation;
 300         int r_num_caps;
 301 };
 302
 303 struct ceph_pool_perm {
 304         struct rb_node node;
 305         int perm;
 306         s64 pool;
 307         size_t pool_ns_len;
 308         char pool_ns[];
 309 };
 310
 311 /*
 312  * mds client state
 313  */
 314 struct ceph_mds_client {
 315         struct ceph_fs_client  *fsc;
 316         struct mutex            mutex;         /* all nested structures */
 317
 318         struct ceph_mdsmap      *mdsmap;
 319         struct completion       safe_umount_waiters;
 320         wait_queue_head_t       session_close_wq;
 321         struct list_head        waiting_for_map;
 322         int                     mdsmap_err;
 323
 324         struct ceph_mds_session **sessions;    /* NULL for mds if no session */
 325         atomic_t                num_sessions;
 326         int                     max_sessions;  /* len of s_mds_sessions */
 327         int                     stopping;      /* true if shutting down */
 328
 329         atomic64_t              quotarealms_count; /* # realms with quota */
 330
 331         /*
 332          * snap_rwsem will cover cap linkage into snaprealms, and
 333          * realm snap contexts.  (later, we can do per-realm snap
 334          * contexts locks..)  the empty list contains realms with no
 335          * references (implying they contain no inodes with caps) that
 336          * should be destroyed.
 337          */
 338         u64                     last_snap_seq;
 339         struct rw_semaphore     snap_rwsem;
 340         struct rb_root          snap_realms;
 341         struct list_head        snap_empty;
 342         spinlock_t              snap_empty_lock;  /* protect snap_empty */
 343
 344         u64                    last_tid;      /* most recent mds request */
 345         u64                    oldest_tid;    /* oldest incomplete mds request,
 346                                                  excluding setfilelock requests */
 347         struct rb_root         request_tree;  /* pending mds requests */
 348         struct delayed_work    delayed_work;  /* delayed work */
 349         unsigned long    last_renew_caps;  /* last time we renewed our caps */
 350         struct list_head cap_delay_list;   /* caps with delayed release */
 351         spinlock_t       cap_delay_lock;   /* protects cap_delay_list */
 352         struct list_head snap_flush_list;  /* cap_snaps ready to flush */
 353         spinlock_t       snap_flush_lock;
 354
 355         u64               last_cap_flush_tid;
 356         struct list_head  cap_flush_list;
 357         struct list_head  cap_dirty;        /* inodes with dirty caps */
 358         struct list_head  cap_dirty_migrating; /* ...that are migration... */
 359         int               num_cap_flushing; /* # caps we are flushing */
 360         spinlock_t        cap_dirty_lock;   /* protects above items */
 361         wait_queue_head_t cap_flushing_wq;
 362
 363         /*
 364          * Cap reservations
 365          *
 366          * Maintain a global pool of preallocated struct ceph_caps, referenced
 367          * by struct ceph_caps_reservations.  This ensures that we preallocate
 368          * memory needed to successfully process an MDS response.  (If an MDS
 369          * sends us cap information and we fail to process it, we will have
 370          * problems due to the client and MDS being out of sync.)
 371          *
 372          * Reservations are 'owned' by a ceph_cap_reservation context.
 373          */
 374         spinlock_t      caps_list_lock;
 375         struct          list_head caps_list; /* unused (reserved or
 376                                                 unreserved) */
 377         int             caps_total_count;    /* total caps allocated */
 378         int             caps_use_count;      /* in use */
 379         int             caps_reserve_count;  /* unused, reserved */
 380         int             caps_avail_count;    /* unused, unreserved */
 381         int             caps_min_count;      /* keep at least this many
 382                                                 (unreserved) */
 383         spinlock_t        dentry_lru_lock;
 384         struct list_head  dentry_lru;
 385         int               num_dentry;
 386
 387         struct rw_semaphore     pool_perm_rwsem;
 388         struct rb_root          pool_perm_tree;
 389
 390         char nodename[__NEW_UTS_LEN + 1];
 391 };
 392
 393 extern const char *ceph_mds_op_name(int op);
 394
 395 extern struct ceph_mds_session *
 396 __ceph_lookup_mds_session(struct ceph_mds_client *, int mds);
 397
 398 static inline struct ceph_mds_session *
 399 ceph_get_mds_session(struct ceph_mds_session *s)
 400 {
 401         refcount_inc(&s->s_ref);
 402         return s;
 403 }
 404
 405 extern const char *ceph_session_state_name(int s);
 406
 407 extern void ceph_put_mds_session(struct ceph_mds_session *s);
 408
 409 extern int ceph_send_msg_mds(struct ceph_mds_client *mdsc,
 410                              struct ceph_msg *msg, int mds);
 411
 412 extern int ceph_mdsc_init(struct ceph_fs_client *fsc);
 413 extern void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc);
 414 extern void ceph_mdsc_force_umount(struct ceph_mds_client *mdsc);
 415 extern void ceph_mdsc_destroy(struct ceph_fs_client *fsc);
 416
 417 extern void ceph_mdsc_sync(struct ceph_mds_client *mdsc);
 418
 419 extern void ceph_invalidate_dir_request(struct ceph_mds_request *req);
 420 extern int ceph_alloc_readdir_reply_buffer(struct ceph_mds_request *req,
 421                                            struct inode *dir);
 422 extern struct ceph_mds_request *
 423 ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode);
 424 extern void ceph_mdsc_submit_request(struct ceph_mds_client *mdsc,
 425                                      struct ceph_mds_request *req);
 426 extern int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
 427                                 struct inode *dir,
 428                                 struct ceph_mds_request *req);
 429 static inline void ceph_mdsc_get_request(struct ceph_mds_request *req)
 430 {
 431         kref_get(&req->r_kref);
 432 }
 433 extern void ceph_mdsc_release_request(struct kref *kref);
 434 static inline void ceph_mdsc_put_request(struct ceph_mds_request *req)
 435 {
 436         kref_put(&req->r_kref, ceph_mdsc_release_request);
 437 }
 438
 439 extern void ceph_send_cap_releases(struct ceph_mds_client *mdsc,
 440                                    struct ceph_mds_session *session);
 441
 442 extern void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc);
 443
 444 extern char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *base,
 445                                   int stop_on_nosnap);
 446
 447 extern void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry);
 448 extern void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session,
 449                                      struct inode *inode,
 450                                      struct dentry *dentry, char action,
 451                                      u32 seq);
 452
 453 extern void ceph_mdsc_handle_mdsmap(struct ceph_mds_client *mdsc,
 454                                     struct ceph_msg *msg);
 455 extern void ceph_mdsc_handle_fsmap(struct ceph_mds_client *mdsc,
 456                                    struct ceph_msg *msg);
 457
 458 extern struct ceph_mds_session *
 459 ceph_mdsc_open_export_target_session(struct ceph_mds_client *mdsc, int target);
 460 extern void ceph_mdsc_open_export_target_sessions(struct ceph_mds_client *mdsc,
 461                                           struct ceph_mds_session *session);
 462
 463 extern int ceph_trim_caps(struct ceph_mds_client *mdsc,
 464                           struct ceph_mds_session *session,
 465                           int max_caps);
 466 #endif